Why are liquids usually difficult to compress?
a. their atoms are held in position
c. liquids have a definite shape
b. their atoms are already packed closely together
d. liquids are not difficult to compress

b. Their atoms are already packed closely together

Explanation:

Solid state : It is a state in which the particles are closely packed and they can not be compressed.The particles do not have any space between them. They have least kinetic energy due to restricted movement. This state has a definite shape and volume.  

Liquid state: It is a state in which the particles are present in random and irregular pattern. The particles are closely arranged and thus can not be compressed but they can move from one place to another and thus have higher kinetic energy as compared to solids. This state has a definite volume but does not have a fixed shape.

Gaseous state : It is a state in which the particles are loosely arranged and have a lot of space between them. They can be easily compressed. They have highest kinetic energy. This state has indefinite volume as well as shape.

the tides are influenced by both the moon and the sun, it's easy to see that when the sun lines up with the moon and the earth, as during a new moon or full moon, the tidal effect is increased. these are known as spring tides, named not for the season, but for the fact that the water "springs" higher than normal. on the other hand, if the sun and the moon are 90 degrees apart in relation to an observer on earth as during the first quarter moon or third quarter moon, then high tides are not as high as they normally would be. this is because despite its greater distance, the sun's mass allows it to exert enough gravitational force on the oceans that it can negate some of the effects of the moon's pull. this phenomenon of lower high tides is called a neap tide. if you need more information on this topic visit moonconnection.com.

it takes on an electronical energy